1. Field of the Invention:
The present invention relates to improvements of a stapler for driving an inverted U-shaped staple and binding objects such as sheets of paper together by the driven staple passing therethrough.
2. Description of the Prior Art:
The inventor has previously proposed a stapler comprising a base section having an anvil provided thereon at the forward end, a frame section containing a set of steel staples and biasing them forwardly, said frame section including a through-opening portion formed therein at the forward end and aligned with each other, and a handle section pivotally mounted on the frame section on the side opposite to the base section and having an actuating member at the forward end of said handle section, said actuating member being adapted to penetrate said through-opening portion and then to drive the forwardmost one of said staples from said frame section toward the anvil on said base section, all of said base, frame and handle sections being made of a plastic material, said actuating member being molded integrally with said handle section and including a thick-walled reinforcing portion formed thereon. This construction is very advantageous in cost of manufacturing since the actuating member is formed integrally in the handle section using the same material as that of the handle section without need of mounting a separate steel piece on the handle section. However, the actuating steel member easily slips at its bottom face on the steel staple to promote wearing at the bottom face of the actuating member. Even if the bottom edge of the actuating member is slightly worn, the slippage is increased between the top of a staple and the bottom face of the actuating member. As a result, a staple cannot properly be driven downwardly and bind sheets of paper satisfactorily. Therefore, the stapler may become ineffective before the service life of the parts including the actuating member expires.